Technically, font healing is a neat idea. It fails for text that does not meat its requirements, i.e. two 'm' next to each other. Depending on the characters around them, this might create two different 'm'.
This is unavoidable, of course. The only solution are proportional fonts. So font healing is a nice idea. It creates a more consistent spacing at the price of less consistent glyphs. Whether one likes this compromise, is a matter of taste. I personally lean towards consistent glyphs, but I did not try it for an extended period.
